SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35e6e9c8289eca85570f51fd64b3cecb876d7292e1cb1c80d775e698a0a7e9a4' 
  AND token = 'EfYJZt7ZV7pqO9NFRvnulj2hjj6J+FPi4os29Ww/zOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}